Difference between biological and non biological washing powder

Im not sure what the difference is between biological and non biological washing powder. Is the biological one better for the environment? In terms of quality of wash and protection of colours which one of the two is the better one to use?

ah...so biological is stronger and is ok for whites but tends to discolour? Is this the only difference in the powders then? Is it universally known that biological is more effective at cleaning? Is this why it is still being sold rather than just having non biological?

What is the difference between Biological and Non-Biological Powder? A label in one of my tops said to use Non-Bio powder, but I read this after it had been washed with Bio, and the top was all static...